Ammonium hydroxide polymer solutions for floor polish compositions



United States Patent 3,488,311 AMMONIUM HYDROXIDE POLYMER SOLUTEONS FORFLOOR POLISH COMPOSITIONS Donald L. Burdick, Overland Park, Kans., andWilliam J. Hellman, Allison Park, and Gerald J. Mantell, Allentown, Pa.,assignors to Gulf Research & Development Company, Pittsburgh, Pa., acorporation of Delaware No Drawing. Filed Jan. 19, 1967, Ser. No.610,253 Int. Cl. C09g N16 US. Cl. 26029.6 1 Claim ABSTRACT OF THEDISCLOSURE In the manufacture of floor polish of the aqueous dispersiontype, it is now common practice to include in polish formulations anaqueous solution of an ammonium salt of a carboxy-substituted polymericproduct derived from a copolymer of styrene and maleic anhydride.Soluble resins of this type are often referred to as leveling resins.The polishes made with the use of polymer solutions of this type showimproved heelmark-resistance, lighter color and better thermal stabilitythan the prior art polish formulations. However, they are somewhatdeficient in many formulations, particularly with respect torecoatability and waterspot resistance. These defects appear to beassociated with poor compatability with some of the other ingredients inpolish formulations.

A class of soluble resins has now been discovered which are morecompatible with the ingredients of polish formulations and confer onthese aqueous dispersion polishes better coatability, recoatability,gloss, jetness, transparency, leveling and resistance to Waterspotting,while maintaining the good heelmark-resistance, light color and thermalstability of the modified styrene-maleic anhydride copolymers.

Briefly, the new ammonium hydroxide soluble resins are partiallyesterified copolymers of maleic anhydride with an olefin selected fromthe group consisting of l-hexene, l-butene dimers, l-octene and l-decenein olefin/maleic anhydride molar ratios of from about 1 to 1.5, whichhave acid numbers of at least 150, are substantially free from anhydridestructures and adjacent free carboxy groups,'at least half of thecarbonyl groups being present in the form of esters of primary alcoholshaving from one to four carbon atoms, the inherent viscosity of thecopolymers measured at 77 F. (25 C.) in acetone being within the rangeof about 0.04 to 1.1 deciliters per gram (at g./dl. conc.). Anespecially preferred resin is the partially esterified approximatelyequimolar copolymer of l-hexene with maleic anhydride in which abouthalf of the available carboxy groups are present in the form of themethyl ester. This resin, in addition to other advantages over thestyrene-maleic acid copolymers, can be dissolved in aqueous ammoniumhydroxide at room temperature, without heating, to yield solutions ofrelatively high solids content at low viscosity.

The improved floor polish compositions which employ the new resinscomprise an aqueous solution of the ammonium salt of a partiallyesterified copolymer of maleic ice anhydride with an olefin selectedfrom the group consisting of l-hexene, l-butene dimers, l-octene andl-decene having an olefin/maleic anhydride molar ratio from about 1 to1.5, which have acid numbers of at least 150, are substantially freefrom anhydride structures and adjacent free carboxy groups, about halfof the carbonyl groups being present in the form of esters of primaryalcohols having from one to four carbon atoms, the inherent viscosity ofthe copolymer being within the range of about 0.04 to 1.1 dl./g., atleast one other resin or a Wax in aqueous dispersion, and at least oneorganic solvent.

Suitable resins for manufacture of the improved polish compositions maybe made as described below.

Maleic anhydride will copolymerize readily with l-olefins, includingl-hexene, l-olefins made by dimerization of l-butene and various 8- to10-carbon l-olefins. The process generally consists of polymerization insolution in a convenient solvent such as benzene at a temperaturebetween about 60 and 100 C., initiated with a free radical initiator as,for example, about 2 to 3 weight percent of benzoyl peroxide based onmaleic anhydride. An excess of l-olefin, preferably in a molar ratio ofabout 2:1 is customarily employed in order to increase the conversion ofmaleic anhydride to copolymer. The molecular weight may be reduced asdesired by use of chlorinated hydrocarbon chain-transfer agents such ascarbon tetrachloride. The following procedure is given for illustrativepurposes.

l-hexene and maleic anhydride are conveniently copolymerized in solutionin propylene dichloride. The polymer is formed either in solution or ina second liquid phase, depending upon the amount of solvent and monomerpresent. l-hexane acts as a non-solvent for the polymer, and as theratio of hexene to propylene chloride is increased, the polymer forms ina separate liquid phase, as indicated in the table below. In a typicalpolymerization the volume of propylene dichloride may be kept at twicethe volume of hexene and the reaction system will remain a single liquidphase. The polymer is then conveniently recovered by precipitation uponthe addition of an aliphatic hydrocarbon such as heptane. When about twovolumes of heptane per volume of propylene dichloride are mixed with theproduct solution at room temperature, a fine, easily filterable polymerpowder is precipitated in suspended form. Unreacted male'ic anhydridecan be removed by leaching with boiling heptane or octane. If thereaction is carried out at about80 C. for 12 to 14 hours with at least.01 mole of benzoyl peroxide per mole of maleic anhydride, essentiallyall of the maleic anhydride is reacted, so that leaching of unreactedmaleic anhydride from the product is unnecessary. The polymer, afterfiltering, may be dried under vacuum to remove residual hydrocarbons.The solvents employed and the unreacted l-hexene are normally separatedby distillation and recycled to the process.

TABLE I.-COPOLYMERIZATION OF l-HEXENE WI'llI MALEIC ANHYDRIDE Charge:

1,000 cc. propylene dichloride. 106 to 784 grams maleic anyydrido (2-8moles). 4.84 grams benzoyl peroxide (0.02 mole).

Hcxene, Temp.,

cc. C. Appearance employing a hexene to 2 Following the procedureoutlined above mole ratio of reagents of about 4 moles of moles ofmaleic anhydride with .02 mole of benzoyl peroxide, essentially completeconversion of maleic anhydride to a copolymer containing approximatelyequimolar proportions of olefin and maleic anhydride is obtained atabout 80 C. within ten to twelve hours. The polymer product recovered byfiltration is then esterified by reacting with alcohols such asmethanol, ethanol, propanol or butanol.

The catalyst for this reaction can be any material having an ionizationconstant at 25 C. of at least about 1 10 Suitable catalysts includeliquid mineral acids having the required ionization constants, forexample, sulfuric, hydrochloric, nitric and phosphoric acids; organicacids, such as benzene sulfonic and p-toluene sulfonic acids which arereadily soluble in the reaction medium; and solid acidic materialsincluding, but not limited to ion exchange resins. The mineral acidsnormally come in aqueous solution and concentrations in aqueous solutionbetween 25 percent and 100 percent are suitable. Concentrations of acidbelow about 25 percent are especially unsuitable when the higher carbonnumber (above 4) alcohols are employed since the more dilute acid willcause formation of a separate aqueous phase in the reactor.

The amount of liquid acid catalyst employed can vary over a wide range.Usually the weight percent of anhydrous acid based on the weight ofcopolymer is between 0.05 and 5, preferably between 0.1 and 1 weightpercent.

The esterification reaction occurs by contacting the anhydride andalcohol charge stocks at a temperature and for a time sufficient toresult in the formation of the halfester. The reaction temperature issuitably between 40 and 180 C. The initial reaction temperature can bean elevated temperature of between, for example, 100 to 120 C., but atleast the final portion of the reaction must be run at a temperaturebelow about 80 C. for a time sufiicient to convert substantially all ofthe anhydride groups to half-ester groups. It has been discovered that,in order to obtain a substantially pure half-ester compound, i.e., freeof cyclic anhydride groups, from the reaction of the copolymer anhydridewith an alcohol, the reaction temperature during at least the finalportion of the esterification reaction, and the temperature during therecovery of the half-ester must be maintained below about 80 C. Attemperatures above about 80 C., the half-ester compounds formed inaccordance with this invention tend to decompose, yielding cyclicanhydride structures and alcohol, especially under conditions such asmay exist in a drying oven, where the alcohol is removed as it isformed. In order to obtain a faster rate of reaction initially, it isfeasible to employ a reaction temperature between 80 C. and 180 C.,usually between 100 C. and 120 C., so long as the final portion of theesterification reaction is run at a temperature less than about 80 C.,and sufficient alcohol is maintained in contact with the anhydridecompound to assure formation of the half-ester.

The reaction pressure is not critical, but should be such that thereactants and products are maintained in the liquid phase. Suitablereaction pressures include atmospheric to 100 p.s.i.g. or higher.

The preferred alpha olefin-maleic anhydride copolymers are initiallyinsoluble in the alcohol and gradually dissolve in the alcohol as thehalf-ester is produced. Suflicient alcohol is normally employed to notonly serve as a reactant, but to serve as a solvent for the system. As apractical matter, the volume ratio of alcohol to the anhydride form ofthe copolymer is usually between 20:1 and 100:1, which assures formationof a product solution with a viscosity low enough to make the solutioneasy to handle, i.e. to pump or stir.

If desired, stoichiometric amounts of alcohol can be employed togetherwith a mutual solvent for the reactants. Suitable mutual solventsinclude benzene, acetone, 2-butanone, propylene chloride, andiso-octane. However, the use of a mutual solvent involves added expenseand difiiculties in the separation of products.

The reaction time should be sufficient to result in the formation of thedesired half-ester. The usual reaction time is between 0.5 and 24 hours.The exact reaction time can be determined by following the reaction withsuitable means, such as with infrared analysis until the anhydridecarbonyl absorption peak disappears, that is, by periodically removingsamples and subjecting them to analysis, such as infrared, to determineif any carbonyl groups are present as anhydride groups. This time can beshortened by the initial use of high temperatures, but the completion ofthe reaction, usually the last 20 to 60 minutes, must be at atemperature below 0., usually between 40 and 60 C.

The reaction can be run in a batch or continuous manner or through acoil type reactor.

The reaction products are recovered by any suitable pro cedure. If it isdesirable to recover the half-ester substantially free of anhydride, thetemperature during the recovery procedure must at all times bemaintained below about 80 C., preferably between 0 C. and 60 C.Halfesters prepared by using alcohols having between 1 and 4 carbonatoms can be recovered in a solid particulate form by precipitating thehalf-ester from reaction solution by contact with an excess of water ata temperature below 80 C., preferably room temperature. The half-estersare recovered by filtration, are washed with water to remove any tracesof alcohol and acid catalyst and are then dried under a vacuum(preferably a pressure of between 1 and 50 mm. of Hg) at a temperaturesuitable to obtain the product desired. To obtain a productsubstantially anhydride free, temperatures less than 80 0., preferablybetween 0 and 60 C. should be employed. An inert dry gas, such asnitrogen, can be passed over the SOlld halfester to aid in the dryingprocess. By dry is meant substantially free, i.e., less than 2 weightpercent, of physically bound alcohol. The particulate solid half-esterobtained by this procedure is pure white in color. A typical half-esterpreparation is specifically exemplified below.

In this example, 237.4 grams of equimolar l-hexene-- maleic anhydridecopolymer and 662.4 milliliters of methanol were employed along with2.37 grams of percent phosphoric acid. The weight percent of anhydrousacid based on the copolymer was 0.85. The reactlon was run forv 10.5hours at 64 C. Nine samples were taken over the course of the reactionand subjected to infrared analysis to determine the anhydride carbonylcontent of the reaction mixture. The reaction was terminated when theninth sample indicated the absence of anhydride carbonyl absorptionpeaks. A yield of 262.1 grams of dried polymer was obtained. The polymerhad a dilute solution v1 scosity in acetone of 0.078 deciliter per gram,and an acid number of 256. The theoretical acid number for the purehalf-ester was 262. The sample was subjected to nuclear I magneticresonance to determine the carbonyl content of the sample present asacid, anhydride and ester. The data from these analyses indicated theabsence of anhydride structures and the presence of 59.2 mole percent ofthe carbonyl groups as free acid, the balance being present 1n the estergroups.

Below are tabulated the properties of several other copolymers of maleicanhydride with various olefins and esters thereof, made according to theprocedures outlined and exemplified above:

Inherent viseosities measured in acetone at 77 F. and a concentration of5 grams per deciliter.

INFLUENCE OF ALCOHOL CHAIN LENGTH With increasing length of the alcholcarbon chain there is decreasing solubility in aqueous ammonia,increasing viscosity in solution, slight decrease in compatibility withother polish ingredients and some decrease in performance evaluation ofpolishes. Primary alcohols of one to four carbon atoms are found to givethe best performance in polish formulations.

INFLUENCE OF ACID NUMBER With increasing acid number the solubility inaqueous ammonia increases and there is an increasing tendency of polishfilms to be Water-sensitive. Acid numbers should be sufiiciently high toassure solubility (about 150) but no higher than the theoretical valuefor 50 percent ester for consistently good performance. In productswhich have been esterified beyond the 50 percent level, there arepresent some adjacent carbalkoxy structures. These have a tendency toreduce solubility, particularly in higher molecular weight copolymersand when the esters are propyl or butyl. If consistently good solubilityin aqueous ammonia is desired, it is best to terminate esterificationwhen the acid number of the product is approaching the theoretical valuefor the half ester. In the preferred polymers, polish performance isbetter with respect to durability and other properties. For satisfactoryperformance, the molecular weight should be sufiiciently low to assuresolubility and a solution viscosity which is low enough for convenientuse in formulating polishes. The inherent viscosity of the copolymershould be from about 0.04 to 1.1, preferably from 0.05 to 0.5, with anacid number approaching the theoretical value of the halfester,preferably about 185 to 250 for best all-around performance in a varietyof polish formulations. For outstanding ease of formulation, theproducts of lower inherent viscosity and higher acid number are moredesirable. Such products dissolve more readily, form less viscoussolutions, are very compatible with other polish ingredients and arevery consistent in giving good performance. The use of a versatileproduct of the latter type is specifically exemplified below.

There was dissolved in aqueous ammonium hydroxide a methyl ester of acopolymer of hexene and maleic anhydride prepared according to theprocedure described above, yielding a solution of workable viscosity at20 percent solids content. The methyl ester copolymer had a softeningpoint of approximately 131 C., an acid number of 250, an inherentviscosity of 0.06 and was obtained by esterification of an approximatelyequimolar copolymer of l-hexene with maleic anhydride. Three polishformulations were prepared having a 15 percent solids content andemploying the copolymer ester solution. The compositions of the threeformulations are indicated in the products the distribution of carboxyand carbalkoxy following table:

TABLE II.15% SOLIDS POLISH DISPERSIONS Formula Formula Formula II, III,parts parts parts Aqueous Resin Dispersion:

Modified polystyrene latex (Ubatol UL-2001) at 15% 60.0 Modifiedstyrene-acrylic latex (Neocryl A-247) at 15%.. 70. 0 Modified acryliclatex (Rhoplex B-231) at 15% I 72. 5 Aqueous polyethylene dispersion(PolyEm) at 15% 11.0 Hexene-maleic copolymer methyl ester solution at15% 16. 0 Organic Solvents:

Trrbutoxy ethyl phosphate C rbitol Ethylene glyeol Dibutyl phthalate..Butyl benzyl phthalete- Oleic acid groups in the copolymer moleculesappears to be random,

The polish formulations were evaluated on vinyl asas indicated byconventional chemical and physical tests. bestos floor tiles by A.S.T.M.procedures or modifications INFLUENCE OF MOLECULAR WEIGHT Withincreasing molecular weight of the esterified cothereof recommended bythe Chemical Specialties Manufacturers Association. The results appearin the table below.

TABLE TIL-EVALUATION OF POLISH FORMULAS OF TABLE II Polish Formulation III III Single Coat Very Good Good Good.

Excellent Excellent. Recoatability (1 hr.) Very good ..do Do.Waterspotting:

2 hr Moderate Slight Moderate.

Slight to very slight "do. Moderate to slight.

G d Good. Good.

Excellent.

Haze I. Oven Stability (30 days):

Initial pH 9.3 Final pH 9.3 9.3 Haze Very slight Slight No.

1 Very good gloss and jetness. 2 GSA No. 1 Control, 0.36.

Environmental Conditions: Temperature, 72 F., Relative Humidity, 47%.

A corresponding propyl ester was made by esterification of the copolymerof l-hexene and maleic anhydride. The propyl ester had a softening pointof 106 C., an acid number of 212 and dissolved readily in aqueousammonium hydroxide. The solution of the propyl ester in ammoniumhydroxide was employed in three polish formulations corresponding toFormulas I, II and III above which were tested on vinyl asbestos floortiles. The results obtained were substantially equivalent to those whichappear in Table 'IH. The only significant difference which appeared inthe results was in heelmark resistance, which only rated good. Thisdifference in behavior is probably attributable to the lower softeningpoint of the propyl ester. The gloss, leveling, recoatability and waterspotting resistance in all instances were consistently better whencompared with the performance of a corresponding commercial ammoniumhydroxide-soluble styrenemaleic acid resin.

In addition to the ammonium salts, the half-ester copolymers of thepresent invention also form water-soluble salts with variouswater-soluble amines such as morpholine or the eth anolamines. Theaqueous solutions of amine salts are equally useful in formation ofimproved floor polishes. However the ammonium salts are preferredbecause they are cheap and quickly yield good polish coatings which areodorless, colorless, durable and yet are easily removed prior torecoating.

The half-ester copolymers of the present invention are suitable for usein heavy duty bufiable polishes and in dry-bright polish formulations ofthe type which yield finishes which are resistantto detergents and aretherefore washable, but which are readily removable with aqueousammonia. The compositions of typical formulations are tabulated below,along with formulations employing a modified styrene-maleic anhydridecopolymer, for purposes of comparison.

Formulation 1 showed the best resistance to detergents, while beingreadily removable with detergents containing ammonia.

Formulation 5 was applied to vinyl asbestos tile and evaluated accordingto bench test procedures, as in Table III. Results are tabulated below.

Table VI.Evaluation of Formulation No. 5

The performance of the novel copolymer half-esters was clearlysatisfactory in this heavy buifable industrialtype polish formulation.

What is claimed is:

1. The floor polish composition comprising an aqueous solution of theammonium salt of a partially esterified copolymer of maleic anhydridewith an olefin selected from the group consisting of l-hexene, l-butenedimers, l-octene and l-decene in a molar ratio of olefin to maleicanhydride of from about 1 to 1.5, which has an acid number of at least150, is substantially free from anhydride structures and adjacent freecarboxy groups, at least half of the carbonyl groups in said copolymerbeing TAB LE IV.DETE R GENT-RE SISTANT POLISH F0 RMULATIONS Formulations1-4 are detergent resistant polishes. These were tested for ability ofthe polish coating to resist three cleaning compositions. Results wereas follows:

4, parts 5, parts present in the form of esters of primary alcoholshaving from one to four carbon atoms, said copolymer having an inherentviscosity in the range of about 0.04 to 1.1

TABLE V.NUMBER OF STROKES TO REMOVE FINISH Formulation CleaningComposition 1 2 3 4 (1) 1.5% solution of laundry detergent (Tide)200(10%) 200(40%) 200(75%) 131 (2) Industrial soap solution with 0.5%NHlOH 86 44 88 (3) 1.5% solution of laundry detergent plus 2.8% NH4OIL-.. 40 48 26 19 9 10 deciliters per gram measured at a concentrationof 5 g- FOREIGN PATENTS per deciliter in acetone at 25 C., incombination with 201 429 2/1955 Australia a major amount of an aqueousdispersion of at least one other resin and a minor amount of an organicsolvent, MURRAY TILLMAN, Primary Examiner References Cited 5 W. I.BRIGGS, SR., Assistant Examiner UNITED STATES PATENTS US. Cl. X.R.3,236,797 2/1966 William 26028.5, 30.6, 31.2, 31.8, 33.4, 78.5, 897, 901

3,328,328 6/1967 Scanley 260-285

